The present invention relates generally to a carrier for supporting a hard drive in a personal computer (PC) system. More particularly, the present invention relates to a carrier design which facilitates the blind mating of a connector assembly to an internal connector in a housing. Still more particularly, the present invention relates to a one-piece carrier body for supporting a hard drive, which permits an interface connector to float in three dimensions to facilitate blind mating within a hard drive bay.
The components provided in a PC system typically comprise a combination of fixed, internal devices, and peripheral external devices that may be added to the PC system to increase the computing power or to add features not included as part of the fixed PC system supplied by the manufacturer. The PC system, for example, typically includes a motherboard on which most of the fixed internal processing circuitry of the PC is mounted. While working memory (such as random access memory or RAM) may be mounted on the motherboard, typically permanent memory devices are not.
In most computer systems, permanent memory is provided in a memory hard drive, or hard disk. The term "hard" is used to indicate that this type of drive or disk is fixedly installed in the PC system, unlike a floppy drive, which is very easily removable. Hard drives typically are made of metal or plastic disks that are coated with a ferromagnetic material The disks usually have a standard thickness, and are available in a variety of sizes. In conventional hard drives, a plurality of disks are mounted in a cartridge pack, with supporting interface electronics to support hard disk services and to expedite the transfer of data between the hard drive and the computer system. Hard drives capable of storing in excess of 1 Gigabytes of data have become commonplace in personal computing systems and file servers (jointly referred to herein as "PC systems" or "computer systems").
In the past, hard drives were considered fixed memory assets of the PC system. More recently, however, it has become increasingly popular to configure PC systems to permit hard drives to be removed from the PC system Thus, for example, if the hard drive malfunctions, it is removed and replaced with another hard drive. Similarly, if storage space becomes limited in the hard drive, hard drives can be added, replaced, or upgraded. As part of the computer reconfiguration necessary to support this removal of hard drives, computer manufacturers now typically configure PC systems with a hard drive bay that is easily accessible by the user. According to conventional techniques, and as shown in FIG. 1, the hard drive bay 5 includes internal connectors 15 for receiving a mating connector assembly 12 on the hard drive package 14. As shown in FIG. 1, in certain computer systems the hard drive bay 5 may be designed to accommodate a plurality of removable hard drives 14.
In an effort to make hard drive replacement easier, many computer manufacturers have developed carriers 7 that are designed to support the hard drives, and to facilitate the insertion and removal of the hard drives 14 in the computer system. Typically, the hard drive 14 mounts on the carrier 7, and the carrier slides into a guide-rail assembly 11 that has been provided in the hard drive bay 5 of the computer system In addition, the carrier 7 typically has mounted thereon the connector assembly 12, which comprises a printed wire assembly (PWA) board. The PWA board connects electrically to the hard drive package 14 to provide a connection interface for the hard drive. The PWA board includes an on-board connector that mates with the internal connectors 15 in the PC hard drive bay 5, when the hard drive carrier 7 is fully inserted into the bay. The PWA board thus acts as an electrical and a mechanical interface between the hard drive and the internal connectors in the hard drive bay. In addition to providing electrical connections to the hard drive package, the PWA board also connects to a system ground in the computer system to insure proper grounding of the electrical interface to prevent spurious signals.
One of the problems that has developed with the use of removable hard drives arises because the mating of the connectors on the PWA board to the internal connectors in the hard drive bay must be performed blindly. The user typically must grasp the connector assembly end (where the PWA board is mounted), and then must slide the carrier into the hard drive bay, hoping that the connectors on the PWA board mate with the internal connectors in the bay. In many instances, the internal connectors are located ten inches or more inside the external surface of the computer. In addition, the user may not be able to see the engagement of the connectors because the carrier and hard drive must be fully inserted into the hard drive bay before engagement occurs. Moreover, if the PWA board connector does not mate properly with the internal connectors in the hard drive bay, the user will tend to jam the carrier more forcefully in the bay, which could result in damage to the connector assemblies, or to the ground connection between the PWA board and the system ground. Yet another problem is that the PWA board is positioned in the carrier in such a manner that it tends to tilt during engagement with the internal connectors. This phenomena occurs because the carrier body typically is molded of plastic, which requires that all carrier surfaces have some draft (or angle) to permit removal from the mold. Because of this draft on the surfaces bearing against the PWA board, the PWA board will tend to tilt to follow the draft angle.
In an attempt to overcome some of these problems, at least one manufacturer has suggested using a carrier which permits the PWA to move or "float" as the hard drive is inserted in the hard drive bay to facilitate the connection of the PWA to the internal connectors. While this arrangement appears to offer some improvement to the prior systems, it does not completely eliminate the problems outlined above. One deficiency with this system is that the PWA is only permitted to float in the x and y planes. As a result, if the hard drive is placed in the bay with excessive force, the suggested design does not provide any relief to protect the connector assemblies. Secondly, this proposed floating design is constructed out of multiple pieces, requiring increased manufacturing and assembly costs.
Despite the clear and apparent need for a carrier design that provides a three dimensional float, that eliminates the tendency of the PWA board to tilt, and which can be constructed in a one-piece design to minimize molding and assembly costs, to date no such design has been developed.